Stars' Halloween costumes 2012

Pop singer Rihanna is named Queen of the West Hollywood Halloween Carnaval by the City of West Hollywood in celebration of Halloween 2012 at a Halloween party at Greystone Manor Supperclub on Oct. 31, 2012, in West Hollywood, Calif.

Credit: David Livingston/Getty

Country singer Miranda Lambert went as Honey Boo Boo for Halloween, tweeting: "We should both win Supreme titles!"

Credit: Personal Photo/Twitter

Pop singer Ke$ha gets decked out for Halloween 2012.

Credit: Ke$ha/Personal Photo/Twitter

Jennifer Lopez and Casper Smart dress up as hippies for Halloween 2012.

From left, the Abbey's David Cooley, recording artist Rihanna and guest attend Rihanna's Queen of the West Hollywood Halloween Carnaval at Greystone Manor Supperclub on Oct. 31, 2012, in West Hollywood, Calif.

Credit: David Livingston/Getty

Kristin Cavallari hosts the Bing It On Halloween Costume Challenge at Spirit Halloween on Oct. 19, 2012, in New York.